• Title/Summary/Keyword: Scheduling

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Integer Programming-based Operation Sequencing for Multi-operation on Single Machine (정수계획법을 통한 다중작업 수행 단일기계에서의 작업순서 결정)

  • Park, Seonyeong;Shin, Moonsoo
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.3
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    • pp.261-270
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    • 2019
  • With the advent of the Fourth Industrial Revolution, multi-variety production in the up-to-date manufacturing environment is proceeding more rapidly whereby production planning and management have been getting more complicated. Moreover, the need to improve production efficiency through effective operation sequencing is further heightened. Fundamentally, the effective operation sequencing can reduce the set-up of the equipment, efficiently utilize the equipment, shorten the set-up time, and ultimately contribute to productivity improvement. This study deals with the problem of efficient operation sequencing in a situation where a single machine performs multiple operations. The complexity of the problem is very high when compared to the case where only one operation is performed on one machine, which is covered in most existing studies. In this paper, we propose an integer programming model to minimize the number of setups. This study aims at minimizing the number of mold replacement times in the process of processing a given production order for the wiring harness manufacturing process, which is one of the components of automobile electric field. In addition, brief case studies are presented to verify the validity of the proposed mathematical model.

Optimal design and operation of water transmission system (상수도 송·배수시스템의 최적 설계 및 운영 모형 개발)

  • Choi, Jeongwook;Jeong, Gimoon;Kim, Kangmin;Kang, Doosun
    • Journal of Korea Water Resources Association
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    • v.51 no.12
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    • pp.1171-1180
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    • 2018
  • Korea's water transmission system is operated by the nonpressure flow method that flows from highlands to lowlands due to the nature of Korea with many mountainous areas. In order to store water in the highlands, the water pumps are installed and operated. However, In this process, a lot of electrical energy is consumed. therefore, it is necessary to minimize the energy consumption by optimizing the size and operation schedule of the water pumps. The optimal capacity and operation method of the water pump are affected by the size of the tank (distributing reservoir). Therefore, in order to economically design and operate the water transmission system, it is reasonable to consider both the construction cost of the water pump and the tank and the long-term operation cost of the water pump at the step of determining the scale of the initial facilities. In this study, the optimum design model was developed that can optimize both the optimal size of the water pump and the tank and the operation scheduling of the water pump by using the genetic algorithm (GA). The developed model was verified by applying it to the water transmission systems operated in Korea. It is expected that this study will help to estimate the optimal size of the water pump and the tank in the initial design of the water transmission system.

The Application of Fuzzy Logic to Assess the Performance of Participants and Components of Building Information Modeling

  • Wang, Bohan;Yang, Jin;Tan, Adrian;Tan, Fabian Hadipriono;Parke, Michael
    • Journal of Construction Engineering and Project Management
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    • v.8 no.4
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    • pp.1-24
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    • 2018
  • In the last decade, the use of Building Information Modeling (BIM) as a new technology has been applied with traditional Computer-aided design implementations in an increasing number of architecture, engineering, and construction projects and applications. Its employment alongside construction management, can be a valuable tool in helping move these activities and projects forward in a more efficient and time-effective manner. The traditional stakeholders, i.e., Owner, A/E and the Contractor are involved in this BIM system that is used in almost every activity of construction projects, such as design, cost estimate and scheduling. This article extracts major features of the application of BIM from perspective of participating BIM components, along with the different phrases, and applies to them a logistic analysis using a fuzzy performance tree, quantifying these phrases to judge the effectiveness of the BIM techniques employed. That is to say, these fuzzy performance trees with fuzzy logic concepts can properly translate the linguistic rating into numeric expressions, and are thus employed in evaluating the influence of BIM applications as a mathematical process. The rotational fuzzy models are used to represent the membership functions of the performance values and their corresponding weights. Illustrations of the use of this fuzzy BIM performance tree are presented in the study for the uninitiated users. The results of these processes are an evaluation of BIM project performance as highly positive. The quantification of the performance ratings for the individual factors is a significant contributor to this assessment, capable of parsing vernacular language into numerical data for a more accurate and precise use in performance analysis. It is hoped that fuzzy performance trees and fuzzy set analysis can be used as a tool for the quality and risk analysis for other construction techniques in the future. Baldwin's rotational models are used to represent the membership functions of the fuzzy sets. Three scenarios are presented using fuzzy MEAN, AND and OR gates from the lowest to intermediate levels of the tree, and fuzzy SUM gate to relate the intermediate level to the top component of the tree, i.e., BIM application final performance. The use of fuzzy MEAN for lower levels and fuzzy SUM gates to reach the top level suggests the most realistic and accurate results. The methodology (fuzzy performance tree) described in this paper is appropriate to implement in today's construction industry when limited objective data is presented and it is heavily relied on experts' subjective judgment.

Design of an Efficient Control System for Harbor Terminal based on the Commercial Network (상용망 기반의 항만터미널 효율적인 관제시스템 설계)

  • Kim, Yong-Ho;Ju, YoungKwan;Mun, Hyung-Jin
    • Journal of Industrial Convergence
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    • v.16 no.1
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    • pp.21-26
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    • 2018
  • The Seaborne Trade Volume accounts for 97% of the total. This means that the port operation management system can improve port efficiency, reducing operating costs, and the manager who manages all operations at the port needs to check and respond quickly when delays of work and equipment support is needed. Based on the real-time location information confirmation of yard automation equipment used the existing system GPS, the real-time location information confirmation system is a GPS system of the tablet, rather than a port operation system that monitors location information for the entered information, depending on the completion of the task or the start of the task. Network configurations also reduce container processing delays by using commercial LTE services that do not have shading due to containers in the yard also reduce container processing delays. Trough introduction of smart devices using Android or IOS and container processing scheduling utilizing artificial intelligence, we will build a minimum delay system with Smart Device usage of container processing applications and optimization of container processing schedule. The adoption of smart devices and the minimization of container processing delays utilizing artificial intelligence are expected to improve the quality of port services by confirming the processing containers in real time to consumers who are container information demanders.

Design and Evaluation of an Efficient Flushing Scheme for key-value Store (키-값 저장소를 위한 효율적인 로그 처리 기법 설계 및 평가)

  • Han, Hyuck
    • The Journal of the Korea Contents Association
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    • v.19 no.5
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    • pp.187-193
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    • 2019
  • Key-value storage engines are an essential component of growing demand in many computing environments, including social networks, online e-commerce, and cloud services. Recent key-value storage engines offer many features such as transaction, versioning, and replication. In a key-value storage engine, transaction processing provides atomicity through Write-Ahead-Logging (WAL), and a synchronous commit method for transaction processing flushes log data before the transaction completes. According to our observation, flushing log data to persistent storage is a performance bottleneck for key-value storage engines due to the significant overhead of fsync() calls despite the various optimizations of existing systems. In this article, we propose a group synchronization method to improve the performance of the key-value storage engine. We also design and implement a transaction scheduling method to perform other transactions while the system processes fsync() calls. The proposed method is an efficient way to reduce the number of frequent fsync() calls in the synchronous commit while supporting the same level of transaction provided by the existing system. We implement our scheme on the WiredTiger storage engine and our experimental results show that the proposed system improves the performance of key-value workloads over existing systems.

A Chosen Plaintext Linear Attack On Block Cipher Cipher CIKS-1 (CIKS-1 블록 암호에 대한 선택 평문 선형 공격)

  • 이창훈;홍득조;이성재;이상진;양형진;임종인
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.1
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    • pp.47-57
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    • 2003
  • In this paper, we firstly evaluate the resistance of the reduced 5-round version of the block cipher CIKS-1 against linear cryptanalysis(LC) and show that we can attack full-round CIKS-1 with \ulcorner56-bit key through the canonical extension of our attack. A feature of the CIKS-1 is the use of both Data-Dependent permutations(DDP) and internal key scheduling which consist in data dependent transformation of the round subkeys. Taking into accout the structure of CIKS-1 we investigate linear approximation. That is, we consider 16 linear approximations with p=3/4 for 16 parallel modulo $2^2$ additions to construct one-round linear approximation and derive one-round linear approximation with the probability P=1/2+$2^{-17}$ by Piling-up lemma. Then we present 3-round linear approximation with 1/2+$2^{-17}$ using this one-round approximation and attack the reduced 5-round CIKS-1 with 64-bit block by LC. In conclusion we present that our attack requires $2^{38}$chosen plaintexts with a probability of success of 99.9% and about $2^{67-7}$encryption times to recover the last round key.(But, for the full-round CIKS-1, our attack requires about $2^{166}$encryption times)

A Study on the Development of Flight Prediction Model and Rules for Military Aircraft Using Data Mining Techniques (데이터 마이닝 기법을 활용한 군용 항공기 비행 예측모형 및 비행규칙 도출 연구)

  • Yu, Kyoung Yul;Moon, Young Joo;Jeong, Dae Yul
    • The Journal of Information Systems
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    • v.31 no.3
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    • pp.177-195
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    • 2022
  • Purpose This paper aims to prepare a full operational readiness by establishing an optimal flight plan considering the weather conditions in order to effectively perform the mission and operation of military aircraft. This paper suggests a flight prediction model and rules by analyzing the correlation between flight implementation and cancellation according to weather conditions by using big data collected from historical flight information of military aircraft supplied by Korean manufacturers and meteorological information from the Korea Meteorological Administration. In addition, by deriving flight rules according to weather information, it was possible to discover an efficient flight schedule establishment method in consideration of weather information. Design/methodology/approach This study is an analytic study using data mining techniques based on flight historical data of 44,558 flights of military aircraft accumulated by the Republic of Korea Air Force for a total of 36 months from January 2013 to December 2015 and meteorological information provided by the Korea Meteorological Administration. Four steps were taken to develop optimal flight prediction models and to derive rules for flight implementation and cancellation. First, a total of 10 independent variables and one dependent variable were used to develop the optimal model for flight implementation according to weather condition. Second, optimal flight prediction models were derived using algorithms such as logistics regression, Adaboost, KNN, Random forest and LightGBM, which are data mining techniques. Third, we collected the opinions of military aircraft pilots who have more than 25 years experience and evaluated importance level about independent variables using Python heatmap to develop flight implementation and cancellation rules according to weather conditions. Finally, the decision tree model was constructed, and the flight rules were derived to see how the weather conditions at each airport affect the implementation and cancellation of the flight. Findings Based on historical flight information of military aircraft and weather information of flight zone. We developed flight prediction model using data mining techniques. As a result of optimal flight prediction model development for each airbase, it was confirmed that the LightGBM algorithm had the best prediction rate in terms of recall rate. Each flight rules were checked according to the weather condition, and it was confirmed that precipitation, humidity, and the total cloud had a significant effect on flight cancellation. Whereas, the effect of visibility was found to be relatively insignificant. When a flight schedule was established, the rules will provide some insight to decide flight training more systematically and effectively.

Analysis of Influence Factors on the Satisfaction of Viewers on China's CCTV-9 Channel (중국 CCTV-9 채널 시청자의 프로그램 관람 만족도 결정요인 분석)

  • Guo, Yuan;Wang, Zhifeng
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.8
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    • pp.107-116
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    • 2021
  • In recent years, the research on audience satisfaction after watching programs has been carried out in various fields. However, there is no precedent for the study of simply analyzing the influencing factors of audience satisfaction with the newly established CCTV-9 channel. For CCTV-9, how to explore the strategy of industrial development based on the needs of the audience in the era of big data is a very important part. This article exploratively focuses on the influencing factors related to CCTV-9 audience satisfaction. Using questionnaires, 101 samples of the satisfaction with the channel of men and women of different ages, education backgrounds, majors, and incomes were collected to test, and 9 hypotheses were tentatively proposed as relevant influencing factors of channel satisfaction. Through empirical analysis, this research searches for the determinants. The reliability and validity of the measurement were properly analyzed, and all hypotheses were statistically tested. The empirical results show that: subject matter, program format, program scheduling, program broadcast time, channel advertising, simulcast series of documentaries, diversified communication platforms, brand image packaging and audience satisfaction are significantly positively correlated.

The Current Status and Needs Analysis of Interprofessional Education in Korean Medical Colleges (한국 의과대학·의학전문대학원의 전문직 간 교육 현황과 요구 분석)

  • Park, Kwi Hwa;Yu, Ji Hye;Yoon, Bo Young;Lee, Dong Hyeon;Lee, Seung Hee;Choi, Jai-jeong;Park, Kyung Hye
    • Korean Medical Education Review
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    • v.24 no.2
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    • pp.141-155
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    • 2022
  • The purpose of this study was to investigate the current status of interprofessional education (IPE) and the efforts required to promote, popularize, and implement it in Korea. The IPE status of 40 medical colleges was investigated using a survey with questions regarding the details of IPE, the future plans and necessary support required, and the reasons for not implementing IPE. Thirty-two medical colleges responded, of which 10 are implementing or have implemented IPE. Most of these colleges started IPE in 2018, and the duration of IPE was less than 9 hours. All medical colleges held classes with nursing students. As for the type of IPE, there were independent courses for IPE, one-time special lectures, or partial sessions in one course. Lectures, discussions and presentations, role playing, and high-fidelity simulations were mainly used as educational methods. The support and interest of the dean was the most important facilitating factor. No medical colleges were currently preparing to implement IPE, four colleges had planned IPE but failed to implement it, and 16 had no plans for IPE at all. All medical colleges cited scheduling or cooperation with other majors as the most significant barrier. All the colleges listed their requirements for educational materials, cases, guidelines, and teaching and learning methods for IPE from external institutions. To activate IPE, it is necessary to create an appropriate atmosphere and conditions for developing IPE competencies and a model suitable for the domestic situation. External medical education support organizations should distribute IPE development guidelines and educational materials, form a network between medical colleges with IPE experience, and make efforts to promote the importance of IPE.

Quantification of the CO2 Footprint in Residential Construction

  • Don Mah;Juan D. Manrique;Haitao Yu;Mohamed Al-Hussein;Reza Nasseri
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.525-536
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    • 2009
  • The current residential process adheres to a traditional method of construction involving wood framing on-site on poured concrete foundations which has been widely applied in North America. A conventional residential construction process can include seventeen distinct stages ranging from stake-out to pre-occupancy inspection. The current practice possesses short comings including high construction material wastes, long scheduling timelines, adverse weather conditions, poor quality, low efficiencies and negative environmental impacts from transportation and equipment use. Over CAN $5 billion dollars was spent in the construction sector during 2007 in Canada. Previous findings in CO2 emissions during the construction process of a conventional dwelling emphasize more than 45 tonnes of CO2 emissions. Hence, in Alberta alone during 2007, almost 50,000 residential units would release more than two million tonnes of CO2. These numbers demonstrate the economical and environmental impact in building construction and its relationship with CO2 emissions. The aim of this paper is to quantify the CO2 emissions from the current residential construction process in order to establish the baseline for CO2 emission reduction opportunities. The quantification collection methodology will be approached by identifying the seventeen various stages of construction and quantifying the contributions of CO2 from specific activities and their impacts of work for each stage. The approach of separating these into separate stages for collection will allow for independent opportunities for analysis from various independent contractors from the entire scope of work. The use of BIM will be implemented to efficiently quantify CO2 emissions. Based on the CO2 quantification baseline, emission reduction opportunities such as an industrialized construction process will be introduced that allows homebuilders to reduce the environmental and economical impact of home construction while enabling them to produce higher quality, more energy efficient homes in a safer and shorter period of time.

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